Posted by: westlancashirerecord | December 12, 2016

Burscough Flooding Issues

The theme tune for the Burscough Flooding Group might well be “I can’t get no, oh, no, no, no, hey, hey, hey, that’s what I say, I can’t get no satisfaction” by the Rolling Stones rolling-stones?

On 18 November 2016 the Group secretary Gavin Rattray received a response from the Environment Agency. It might become known as the “rainbow” letter with its colour scheme of yellow, red, and green!

“Dear Gavin
Enquiry regarding Martin Mere, West Lancashire
Thank you for your further questions below in yellow highlighted text. We respond to requests under the Freedom of Information Act 2000 and Environmental Information Regulations 2004. Our answers are below your queries in red text. Please refer to Open Government Licence which explains the permitted use of this information. Please get in touch if you have any further queries or contact us within two months if you’d like us to review the information we have sent.

Carolyn Burns.Customers and Engagement Officer. Cumbria and Lancashire
Environment Agency

26 October 2016 Dear Carolyn
Thank you for your email. Please find my responses to it highlighted in yellow:

• What investigations are the EA currently undertaking to undertaking to establish how instrumental the presence of the Weir, plus the neglect of the maintenance of the sluice itself has had on the frequency and depth of the floods that have occurred in the last ten years culminating in the flood on the 26th December 2015? And what investigations is it undertaking to establish what effect the Weir is having on the groundwater level as measured by the BGS in Burscough?

Survey work has been carried out on the weir and locations around Crabtree Lane after the flooding events in December 2015. This along with LiDAR survey has demonstrated there is little to no chance that the weir has any effect on water levels on Crabtree Lane or in Burscough. Yew Tree Farm sits more than 20 metres higher than the weir at Martin Mere.

A large percentage of the houses on Fish Lane, Tarlscough and Mescar Lane were flooded by groundwater and surface water on Christmas and Boxing Day 2015 (please see the Flood Records attached) the EA has ignored them in its answer, yet they are near the weir.
In addition, EA publication River Weirs – Good Practice Guide in negative impacts of weirs table 1.1, states (at the very top of the table), Increased flood risk, then …. Raised groundwater level …. (restricted drainage).

So again, may I request that the EA please answer my original question, whilst taking all of the flooded properties near (or affected by) the weir into consideration.

There is currently no evidence that the weir has any effect on flood levels or groundwater levels in the areas quoted for the reasons originally stated above. For this reason we cannot justify undertaking further investigation. Flood risk associated with the weir would have been considered as part of the original consenting process.

The Environment Agency’s flood map can be challenged if you feel there are areas at risk of flooding from rivers and sea that are not represented properly. You would be required to submit evidence in the form of a hydraulic model that will then be reviewed by ourselves. If it is the case that the provided evidence demonstrates a more realistic representation of the flood risk than our models, the flood map will be changed.

BFG were tasked with the job of creating a flooding database for Burscough Parish Council and that evidence demonstrated that both groundwater and surface water flooding has occurred in Burscough in the areas close to the weir, i.e. Fish Lane, Tarlscough and Mescar Lane. We supplied that evidence to the EA, to LCC and to WLBC. We also know that some of the flood victims contacted your partner agencies and may have contacted the EA directly. Your survey didn’t look at those areas. Therefore, please answer my original question. “What investigations are the EA currently undertaking to establish how instrumental the presence of the Weir, plus the neglect of the maintenance of the sluice itself has had on the frequency and depth of the floods that have occurred in the last ten years culminating in the flood on the 26th December 2015 [Fish Lane, Tarlscough and Mescar Lane]?”

For your information BFG have found the EAs surface water flooding maps extremely helpful when looking at flooding issues and are very grateful for the time and effort the EA must have put into making them. I would not necessarily question the EAs modelling but would only say that BFG uncovered evidence of significant under reporting of all types of flooding in Burscough and if that has fed into the EAs database as it has with the LLFA, UU and WLBC then it explains why it is so difficult for Burscough Parish Council, BFG and in 2005, WLBC to get the primary causes addressed which we then knew to be inadequacies of UUs foul and surface water drainage network and now also know to also be inadequacies in LCCs surface drainage network, very likely groundwater infiltration into the drains, the restriction of the boathouse sluice due to the installation of a weir 30 years ago which it is rumoured to have been increased in height since it was first installed and a lack of maintenance to the sluice.

• If the installation of the weir 30ish years ago and the neglect of the sluice is the reason so many people’s homes were flooded on boxing day 2015 and before, what processes would the EA need to undertake to remove the Weir altogether and get Martin Mere to clear the sluice of sediment and reeds?

The weir went through the proper Consent process at the time and is deemed to be in good working order. There is no evidence to support the idea that the weir caused any flooding to property.

Bearing in mind that there is evidence that the weir has caused flooding from the EAs own publication and our database. Please would the EA kindly answer the remainder of the question (on a hypothetical basis if necessary), .. what processes would the EA need to undertake to remove the weir altogether and get Martin Mere to clear the sluice of sediment and reeds?

The publication quoted is a guide which considers general risks, which would have been considered in the original consenting process. The Environment Agency would only take enforcement action upon a riparian landowner to carry out maintenance of a watercourse or remove a consented structure if it could be evidenced that the river was in such a condition that the ‘proper flow of water is impeded’. As a fully consented weir is not considered to be a blockage or impediment to flow, there would need to be some form of flood modelling done that evidences that the effects of the weir are directly causing flooding to upstream reaches in order to enforce its removal. With regard to channel maintenance, again it would have to be demonstrated with evidence that the condition of the channel was causing an ‘impediment’ to flow (i.e. if it was silted up, full of debris or blocked by fallen trees or branches) to such a degree that water was surcharging and the blockage was directly causing an increased flood risk to upstream areas.

It is not correct to state that there is no evidence of flooding and that a proper consent was carried out. Your own publication lists flooding, raising of groundwater levels and a reduction in drainage as a side effect of weirs. Houses near the weir were flooded by groundwater and surface water. BFG have reported the flooding to you and your partner agencies.

BFG asked for all documentation you held about the weir under FOI legislation. We didn’t receive a copy of a consent, or any evidence that a consent process was followed at all. In addition, due to the nature of our enquiry we know that the EA couldn’t have legally held back any evidence of a consent, therefore, we know that the EA don’t have a consent for the weir at martin mere and equally cannot have evidence to the adequacy of something that is non-existent.

• How long after the weir is removed would it take for groundwater levels to reduce to their historic normal level and the groundwater flood risk (which spreads as far as the urban areas in Burscough) to also reduce?

We are unable to answer this, but telemetry from the borehole at Yew Tree Farm demonstrates that the current groundwater levels fall within the usual levels expected for this time of year.

I appreciate why you may not be able to answer every question posed but I wonder why you stated what you have done about the groundwater level, when the graphs on the BGS site http://www.bgs.ac.uk/research/groundwater/datainfo/levels/sites/YewTreeFarm.html

clearly shows that groundwater water levels in Burscough have been rising steadily since the 1990s and this year is no exception as does the BGS’s own analysis. Why does the EA not provide the same analysis as the BGS and why does it not seek to warn residents about the flooding risks that it poses? Is protecting people and property from flooding still a fundamental part of the EAs remit or has the EAs remit changed? and if so what to?

The attached YEW TREE FARM GROUNDWATER LEVEL.pdf shows the dip (depth to groundwater) values from the borehole, and this does not rise to within 8m of the measuring datum, and this measuring datum is approximately the same as ground level.

The Yew Tree Farm observation borehole itself is over 3km from the weir, and is monitoring a different bedrock geological unit (sandstone) to that which the weir is located above (mudstone), and is spatially separated by faulting, which generally trends north to south. This is summarised in YTF1.pdf, which uses published geological mapping. The small rise in the water table observed at the borehole is not regarded as being indicative of potential issues with the weir.

The ‘Borehole A’ on the YTF1.pdf is a former groundwater abstraction point, and exploited the same geological unit (sandstone) as the observation borehole at Yew Tree Farm. This licence was revoked during 1999, and the cessation of this abstraction is more likely to be contributing to the groundwater level rise observed at Yew Tree Farm, which can be observed in the YEW TREE FARM GROUNDWATER LEVEL.pdf.

I can accept the EA’s assertion that the high groundwater levels in YTF are unrelated, thank you kindly for explanation. Please understand I am not an expert so what may be obvious to the EA may take me some time to understand and my questions are not put for my amusement. They are an attempt to get the EA to take the problems of residents suffering groundwater and surface water flooding problems seriously, because it is having such a detrimental effect on their lives.

• In addition, although known to be worse than inadequate, Burscough sewers surcharged widely on Boxing day, might that have been made worse by the high groundwater level or not?

We think this is unlikely, however we are unable to confirm.
I find your response quite at odds with a recent email from the EA in response to the same question posed by another member of BFG, who asked, “My research centres around rising groundwater levels especially in the West Lancashire area. My question is, does a rising groundwater level create a greater susceptibility to surface water flooding or poor drainage.”

When the EA wrote,
“Increased infiltration and a rise in the water table may result in more water flowing into rivers which may then be more likely to break their banks. A rise in the water table during periods of higher than normal rainfall may mean that land drainage networks, such as storm sewers, don’t work properly if groundwater is flowing into them underground. This may affect their ability to get rid of surface water which then causes flooding. © UK Groundwater Forum, 2011. All Rights Reserved.

This abstract is taken from the following link. You may also find further groundwater information from this source that may be of interest.”

Please can you explain why the EA sent me such a misleading answer?
We can only answer questions based on data that we hold. As there is no groundwater data other than stated the question remains unanswerable. Obviously a very high groundwater level could affect surfacewater drainage but we do not know if that happened in Burscough in December 2015.

As I stated before, I am not an expert and so was unaware that groundwater flooding can cause or add to sewer flooding until the EA informed another member of BFG that this was likely. You will also find that the LLFA are not experts either, because they stated in their recent S19 report that groundwater flooding wasn’t a factor in the Boxing Day 2015 floods.

The fact that the EA hasn’t informed the LLFA that they are wrong to discount groundwater without investigation and that it provided two completely different answers to effectively the same question, could lead people to perceive that the EA are trying to keep the scale and causes of flooding in Burscough secret from the public. Please may I have an explanation of the EAs behaviour?
Finally, given there is no consent for the weir when are the EA going to examine the weir, speak to local landowners and residents and carry out flood risk assessments along with all of the other normal proper consent procedures that the weir requires?

Regards

Gavin Rattray – Secretary Burscough Flooding Group


Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

Categories

%d bloggers like this: